Hokkaido is the largest prefecture in Japan. Going from town to town can take hours. When I lived in Iwate and Chiba the next town was always quite close and easily accessible by train. Unless you live in a big city in Hokkaido you will have to drive everywhere. If you like to go to concerts or just go out for a night of drinking with friends the lack of public transit makes it impossible. Hotels aren't too expensive but spending an extra 40 dollars to get a hotel room makes you think twice about having a drink when you are in a big city.
Not on the main island. Japan is comprised out of many islands but there are four main islands. Honshu is the main island. Tokyo, Kyoto and Osaka are all on the main island in addition to many large cities. Hokkaido has a few cities like Sapporo, Asahikawa and Hakodate however depending on where you live you might wind up never going to a actual city. I live in the furthest southern point of Hokkaido so getting to Sapporo (the largest city in Hokkaido) is a long and expensive journey. First of all there is no train station in my town so I have to drive to Hakodate which is 2 hours away. Since I drove there I have to put my car in a parking garage which costs about 8 dollars a day. The train ticket to Sapporo is 10,800 yen (about 80 dollars). There is no bullet train in Hokkaido. That means you are riding on a normal train for about 5 hours. So you have pretty much killed an entire day just by getting to Sapporo.
There is a tunnel that goes from Hokkaido to Honshu but once again you are taking a normal train, not a bullet train. So going from Hakodate to Aomori will take you a little over 2 hours. I have to take a bus to the train station which costs another 15 dollars. Once you get to Aomori you can transfer to a bullet train and things instantly get much easier. You can quickly get to anywhere in Japan. It costs 19,000 yen to get to Tokyo from Hakodate by train but it takes about the same amount of time as going to Sapporo.
The main point I want to get across is that transportation is terrible in Hokkaido. I would say that living in Chiba without a car is easier than living in Hokkaido with a car. If you are going to live in Hokkaido you are almost definitely going to need a car. I have a few friends who live in larger cities that don't have cars but if you are moving to Hokkaido for an ALT job with the JET Program there is a really good chance that you won't be living in a big city.
When I did my JET orientation in Tokyo there were tons of people who were going to be flying to Hokkaido and I thought there could be two reasons for this, one Hokkaido is really large so they need a lot of ALTs or two lots of people quit working in Hokkaido because it is a hard place to live. After a year of living here I would say that it probably is two. Living in Hokkaido has been a very difficult experience.
Perhaps if I lived in a larger city it would be different but my town only has 4700 people in it. Before this I lived in a city with 500,000 people and before that 100,000. This is a fishing town. The only jobs you can get here are fisherman, convenience store clerk or working in town hall. All of the teachers in this town were transferred here. Most people who live in this town are not college graduates. Most of the people who graduate from the high school in this town do not go to college. I really miss living in a more cultured area. There are about 3 people who I like in this town but honestly no one really wants to be my friend. I get the feeling everyone is embarrassed about living in this town. People either wound up living here or never got out. I don't think there is any real pride in this town. I asked some of my high school students about if they would ever want to move back to this town like 10 years later and some people said "I would be surprised if this town is still here 10 years later".
Do I want to leave? Yes, of course however, the JET Program is one of the best paying jobs you can get in Japan. Starting at 280,000 yen a month with a 30,000 raise every year for three years, it is far beyond the pay of other jobs. I also have free housing. 260,000 is a pretty standard pay rate for an ALT in Japan plus paying about 40,000 a month for rent gets you down to about 220,000 a month. It is far less than what you would be getting with the JET Program. When I first moved here I was asked if I wanted to re-contract only a few months after living here. I had no idea how much I would grow to dislike it. I want to continue with JET but transfers are almost impossible. I am going to try to become a coordinator for international relations, also known as a CIR, next year. I am waiting for the results from the JLPT N2 and hoping that I passed. Having that on my resume will be a huge boost in terms of being able to make that transfer.
After a year of living in Iwate I had a ton of great memories and same with Chiba. A year of living Hokkaido has left me with little to show for it. I have friends but they live in Hakodate which is over an hour away from me. I used to love going out to eat in Japan but there are no good restaurants in this town. I wind up eating junk all the time. The only places to go out and drink are filled with bitter fisherman who want to try to make fun of you even though you make more money than them and eventually are leaving this town. In short, I hate it here. I can't wait to leave.